Windows 7: Lag on line input

When I listen to line in to my Creative XFi card I get a lag of around 1/4 of a second. Line in comes from an analogue mixer and is fed to an amp via an optical out. Until recently, with my Audigy USB card, I could play along to a YouTube track and record backing and my solo successfully.

The BIOS battery failed and the Audigy failed (unrelated problems): three attempts at replacement have exhibited the same lag,- a Creative USB card, a Terratec USB card and now an internal Creative XiFi card. I need a genius to help me track down the problem (one person who responded to an earlier post seemed to doubt that I'd ever had a lag-free system.. less than helpful). Is there anything in the BIOS which could impact latency? I've turned off the motherboard's internal card and tried every imaginable setting in the Creative software..

I'm running Windows 7 64bit on an i7 PC with 12Gb RAM and, in case it's relevant, two graphics cards. I repeat, however, that everything used to work.

Does your card have ASIO drivers or can you use them? Perhaps your current driver/software already has user configureable buffers?

This way you should be able to adjust the buffers and get the result you are looking for.

Reference:
Audio/Soundcard Settings

The "good old latency" issue. I have a recording studio (using Sonar software) and those of us that have computer based studios latency is a prime issue for our equipment.

Have you run the DPC Latency Checker Download HERE

ASIO was mentioned, The Xfi sound card that I used to have did have ASIO (the reason I uninstalled it - the Creative ASIO was interferring with my studio ASIO hardware).

The CMOS (BIOS) backup battery failure would cause the BIOS to revert to default settings but shouldn't have caused any other problems. Are you sure you have the BIOS settings back to how you originally had them? Not sure what could cause the problem, that you didn't have, unless possibly overclocking????

One other thought, are you actually using the Line In or are you using the What You Hear as the default playback device? I recall someone on the Dell forum was having latency problems with the PC audio and they changed the default playback device from the System Mixer (SoundBlaster calls this What You Hear) to the mic (they were using the mic input) and it got rid (minimized) of their latency problem.

Thanks for your replies, guys: the Creative XiFi card acknowledges the existence of ASIO but I can't see a way to tweak it. I'm not sure what kind of implementation this is. The latency checker is a happy bunny,- yet I get this (to me) huge quarter second double thump if I touch a mic. My prime suspect is also overclocking at the moment as the supplier had clearly done something to the system (when I exited BIOS after switching boot devices it gave overclocking warnings). I'm not at all in to overclocking so am not sure what to tweak.

You should be able to undo any overclocking by setting the defaults for your cpu and ram in the bios.

Although many asus boards have a ridiculous ammount of settings in the bios related to overclocking (Example: "AIClockTwister") its only usually the top few settings that get changed, the other settings are for "fine tuning" stability when running way beyond specification.

For more information you can download you motherboard manual from asus.com.